I've decided to try and create a perforated shearwall calculator since I could not find anything online to my liking. This will be above and beyond my usual spreadsheet calculators so it might take a while to piece together. I'm currently working only on the interface, you can try it here, it is still a bit of a kludge and it works best right now with Google Chrome or Mozilla Firefox, Internet Explorer seems to have some issues with the SVG rendering (something to work on):
http://design.medeek.com/resources/shearwall/perfshearwall_calculator.pl (http://design.medeek.com/resources/shearwall/perfshearwall_calculator.pl)
It doesn't actually calculate anything yet but I think the basic interface is slowly emerging. Let me know what you think and also what features or improvements would make the interface better and easier to use.
I plan on calculating Co using the equations in the SDPWS which will mean that my values will not be as conservative if someone were to use table 4.3.3.5.